A great source of e-book conversion utilities can be found at http://wiki.mobileread.com/wiki/E-book_conversion. There you will find various commercial, opensource and freeware programs that can handle file formats like LRF, CHM, LIT, HTML, PDF, RTF, PDB and DOC and convert them to formats that the Kindle can handle.

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Programming information on how to go about reading the Palm Desktop files can be found here. There are several user submitted code examples in various languages, such as Perl, Java, Python and Visual Basic.